Improvement in glass-presses



VWl 0i ,Glass Press.

Patented Aug. 25, 1863,.

N. FEIS. mllw Vlam ILC.'V

Vincrease with the wear of the machine.

UNITED STATES PATENT OFFICE.

WILLIAM OTIS DAVIS, OF PITTSBURG, PENNSYLVANIA, ASSIGNOR TO JAMES B. LYON AND WM. O. DAVIS, OE SAME PLAGE.

IMPROVEMENT IN vGLASS-PRESSES.

Specification forming part of Leiters Patent No. 39,698, dated August 25, 1863.

To all whom, it may concern.-

Beit known that I, WILLIAM Oris DAVIS, of the city of Pittsburg, in the county of Allegheny and State of Pennsylvania, have invented a new and' useful Improvement in Presses for the Manufacture of Glass; and I do hereby declare the following to be a full, clear, and exact description thereof, reference being had to the annexed drawings, forming part of this specification, in which- Figure l is a perspective representation of of my improved press. Fig. 2 is a vertical section of the bed-plate and working-shaft of the machine.

Myinvention is an improvement on the glasspress for which I obtained Letters Patent of the United States on the 31st day of January, A. H1854, and embraces some of the peculiar features of that invention, while it obviates some of its disadvantages.

The chief object which I have in view in my4 present invention, as well as in the former one, is to secure an accurately vertical movement of the piston-rod and plungerby relieving the piston-rod from all side strain or pressure andthe bed-plate of the press from the pressure of the piston-rod and plunger.

In presses for thc manufacture of glass itis necessary to have a high degree of pressure combined with rapidityof motion, and asufficient length ot stroke to clear the plunger from the mold. To attain this combination it is necessary to apply the pressure by means of a lever, but, as the point of attachment of the piston-rod to a simple lever would move in the arc of a circle, it is obvious that there would be a great tendency in the piston to dep part from a truly vertical path, which would As explained in my specification annexed to my former patent, any inclination of the plunger from an exactly vertical position as it enters the mold in pressing the glass is a serious injury to the process and produces a very inferior article. This is especially the case in fine articles, such as decanters, tumblers, wineglasses, &c., as7 for example, a variation of ond thirty-second of an inch only of the top of the plunger from a truly vertical position will make a dierence in the thickness of the glass on opposite sides equal toone sixteenth of an inch, which would `render the'article entirely unsala-ble.

In my former press this object was much more nearly secured than in those previously used in the manufacture of glass, but the motion ofthe swinging beam and counterpoise over the top of the piston-rod has a tendency in practice to strain the pistonrod and cause it to vary sufficiently from a vertical position to make it unsuitable for" use in the pressing of the finest articles of glassware, such as wineglasses, &c. This practical difficulty increases as the length of stroke of the plunger is enlarged to suit the length of the article to be manufactured, for not only is any variation fromV the perpendicular greater in a long than in a short plunger, and consequently the .difficulty of pressing a long article of glass hollow ware greater than a shorter one, but the necessity for an increased length of arc of motion of the lever involves an increased liability to inclination in the plunger.- To obviate these difficulties by giving a longer stroke to the plunger, by applying the power of the lever to the piston-rod and plunger more nearly in a vertical line, and by so placing the counter-balance as to opera-tel more efficiently in throwing back the lever, without any side strain on the pistonrod, are the objects which I have endeavored to accomplish by my present invention.

In order to enable others skilled in the art to construct and use my improved glass-press, I will proceed to describe more particularly its construction and operation.

The bed-plate a of my press is supported in the usual manner on legs, which are furnished with wheels, to enable the press, which is necessarily heavy, to be moved readily from place to place. The arch c c d, placed perpendicularly across the machine near the front end, is made (as are the other parts of the press) of iron, but may be much lighter than is usual in presses for a similar purpose, because by my invention in the press I am now dcscribing, as well as in my` former patent, neither the arch nor the bed-plate sustain or resist the pressure applied by themachine to the mold and its plunger. The arch must, however, be sufficiently stron g, and so securely attached to the bed-plate as to resist any horizontal side strain, and tosustain the pistourod in its vertical position.

Between the sides c c of the arch is situate the sliding frame s, consisting of two horizontal cross-pieces and two upright end pieces, forming at each end or side of the frame a slide which works on the inner face of the sides c cotl the arch as ways.

A piston-rod, p, passes vertically through v the cross-piece d of the arch, slidingup and down through a bore in the arch carefully turned, so thatl the piston-rod may be held tirmly in position and yet work easily in its box. The upper extremity of the piston-rod has a screw-thread, t, cut on it, which takes iuto ahand-wheel, g, placed in a slot in the horizontal cross-beam m, the piston-rod passing through a smooth bore in the center ot' the cross-beam. l

The lower extremity ofthe piston-rod is rigidly attached to the lower horizontal crosspiece of the sliding frame s s, and thus by turning the hand-wheel g the height ofthe bottom ofthe sliding frame above the level of the bed-plate a. may be regulated at pleasure to suit the various heights of the different molds used on the press.

Below the sliding frame s is a horizontal plate, u, which extends between the sides c c of the arch and slides up and down on them. This lower plate, a, has midway from either end a circular hole, t', the center of which is in the same vertical line as the axis ofthe piston-rod, and the diameter of which is sufficient to allow the plunger k ofthe mold to pass through. The lower plate, u, is designed to rest on the top of the mold just as the point of the plunger (which is attached to the lower end ofthepiston-rod orlower cross-piece of the sliding frame) is about to enter the cavity of the mold. Surrounding the circular hole t' in the lower plate, a, are t'our uprights or pins, c t: v '0, which are firmly attached to it, and around each of which is a spiral spring, w.

An upper plate, u', similar in shape to the lower plate, u, but not so long, is secured to the piston-rod near its lower extremity, and between the two cross-pieces ot' the sliding trame s by a screw-nut, working on screwthreads j', cut on the lower extremity ot' the piston-rod p, by which arrangement the relative height of the plates u u and the sliding frame may be adjusted to suit the depth of stroke into the mold which the plunger is desired tomake. The upper plate, u', slides between the end pieces of the sliding fra-me s und on the pins e c, which pass through it, the plates u a being kept apart by the spiral sprmgsjw w.

Near each end of the cross-beam m is an uprlght guide-rod, e, attached rigidly to the cross-beams, and parallel with and in the same plane as the axis ofthe piston-rod. These two guide-rods e e slide up and down in eyes o o, Src., projecting from the outer face of the two side pieces, c c, ofthe arch. These guiderods aid in preserving the exact perpendicularity of action of the piston-rod and resist any tendency of the cross-beam to yield to lateral strain when the power of the lever is nected with the sides of the arch c c. Eachl rope or chain then descends, and is fastened to a counter balance or weight, r, placed horizontally under the bed-plate a ot the press. j

This counter-balance is sufficiently heavy to raise the sliding frame, piston-rod, and crossbeam when the lever is thrown up by the workman.

By this mode of applying the counter-balance it operates in a vertical line to raise the sliding frame, and has no tendency whatever to strain the piston-rod or cause it to wear uncvenly in its bearings. The counter-poise is also very conveniently situated so as to be entirely out of the way ofthe workman, and its operations on the parts of themachine are more uniform and less jarring than that of a weight attached to an arm projecting from the working-lever q, as is the ordinary arrangement. A

To each extremity of the cross-beam m is pivoted a connecting-rod, l Z, which extends down to a point on each side of the press below the bed-plate a. The lower extremity of each connecting-rod is pivoted to the end of the short arm n of the lever g. The short arm of the lever is made with a recess in it at y, to allow the connecting-rod Z to assume a perpendicular position when the lever q is fully depressed. The fulcrum of the lever q is attached to the shaft z, which extends horizontally across the press immediately under the arch c c d, vand projects beyond the sides of the press on both sides. There is a short arm, n, on each side, to which is pivoted a pitman, l, but it is only necessary to have a lever on one side.

The shaft z works in two journal-boxes, a" af, (see Fig. 2,) one at each side of the press. These journal-boxes a a are not attached directly to the bed-plate a of the press, but to a hollow iron' beam which extends horizontally across the press under the arch c c d, and through which the shaft a passes. This hollow beam b has a projection, c', on its upper side, midway from either end, which is attached to the under side of the bed-plate a in a vertical line under the mold d, as seen in Fig. 2. By this means the downward pressure of the piston-rod p and plunger 7c is sustained by the upward pressure of the hollow beam b at the projection c', so that although the bed-plate a is pressed between the mold d above it and the projection c below it, there is no strain upon the bed-plate whatever.

By placing the fulcrum ot' the lever q below the bed-plate of the press I am enabled to remove it so far from the cross-beam m, through which motion is communicated to the piston-rod p and plunger la, that the length of the short arm a of the lever g may be increased so as to give a long stroke to the plunger without materially increasing the deliection of the connecting-rods l Zt'rom the perpendicular, so that even with a long stroke to the plunger the direction ofthe strain of the lever in drawing down the piston-rod varies but slightly from a vertical line; and, as the lever q is depressed and the pressure increased, the

angle of deflection is rapidly diminished un-v til at the point of greatest pressure the pit- Inan assumes a perpendicular position, as before stated. Thus, by placing the fulcrum of the lever some distance below the top of the pistonrod, instead of placing it above it, as is usual, I am enabled to increase to any desired degree the stroke of the plunger without exposing the piston-rod to any strain which would render it liable to vary from an accurately vertical motion, which is so essential to its successful operation.

What I claim as my invention, and desire to secure by Letters Patent, is*

l. Placing the fulcrum of the lever below the bedplate of the press when the power is applied to the piston-rod at or near its upper extremity, for the purpose of diminishing the angle of deection from the perpendicular of the connecting-rods, and thus preventing any material lateral strain on the piston-rod, and enabling the length of stroke of the piston -rod and plunger to be increased Without interfering with the perpendicularity of this motion.

2. The arrangement of a counter-balance consisting of a weight placed under the bedplate of the press, and connected by chains and pulleys with the moving parts ot' the press, so as to raise them when the pressure on the lever is Withdrawn.

In testimony whereof the said WILLIAM Oris DAVIS has hereunto set his hand in presence of us.

WM. O. DAVIS.

Witnesses:

J. D. HANCOCK, l J. G. ATTERBURY. 

